The Ore Potential of Deep-Seated Zones of Ancient Continental Crust, Based on Data From the Kola Superdeep Drillhole

Unusual Mineral Associations in the Lower Levels of the Kola Superdeep Drillhole

“…In contrast to the electrum reported earlier [6], relatively fine gold is present in the microbreccia (855-892 fine). In some gold grains, iron (1.76%) and silicon (0.57%) were found.…”

“…In the Kola group the drillhole penetrated iron formation and magnetite-ilmenite ores in the amphibolites, copper-nickel sulfide mineralization associated with metamorphosed ulrramafic rocks, low-temperature hydrothermal copper-lead sulfide mineralization in zones of retrograde metamorphism 84 V. I. KAZANSKIY ET AL. [6]: I) rocks, II) metamorphic facies, III) ore mineralization. 1) Volcanics; 2) sedimentary rocks; 3) ultramafics; 4) gneisses with high-alumina minerals; 5) biotite-amphibole gneisses; 6-10) metamorphic facies: 6) prehnite-pumpellyite, 7) greenschist, 8) epidote-amphibole, 9) amphibolite, 10) retrograde greenschist; ore mineralization: 11) copper-nickel sulfide, 12) iron ore in quartzites, 13) iron-titanium, 14) copper-cinnabar, 15) zones of schistosity; 16) gold mineralization.…”

“…Although the gold mineralization coincides spatially with zones of retrograde altera tion superposed on the biotite-amphibolite gneisses of the Kola group, no direct connection between the disseminated gold and the chloritization, serializa tion and epidotization of the host metamorphic rocks was established. Accordingly, the place of the gold mineralization within the overall sequence of endo genic processes and the paragenetic associations of the native gold remained open questions [6].…”

Anniversary of the commencement of the sg-3 Kola superdeep borehole drilling operations

“…For the first time, unique data were obtained on the structure, composition, and temperature characteristics of the deep zones of the earth's crust, physical properties, and geochemical features of deep rocks; the presence of ore mineralization and metal-bearing hydrothermal systems was also proved (Kozlovsky et al, 1988;Orlov &Laverov, 1998). At a depth of 1600-1800 m, researchers discovered ore deposits with industrial types of Cu-Ni ores.…”

“…Thousands of thin sections and polished sections from SG-3 had been thoroughly studied and described. The result of the research activities was a detailed picture of the geological and geochemical features of the borehole rocks, their chemical and mineral composition, and ore content (Kozlovsky et al, 1988;Lobanov et al, 2013Lobanov et al, , 2020. The absolute age of hundreds of rock samples was measured (Bayanova et al, 2000), and the chemical properties and the structure of minerals were described (Skuf'in & Lyutoev, 2009).…”